Judith K Brown

PMID: 11268056;Abstract:

A microscopic analysis of the morphology and ultrastructure of the digestive, salivary, and reproductive systems of adult Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) B type was conducted using light, scanning, and transmission electron microscopy. The internal anatomy of B. tabaci was found to be similar to that reported for Trialeurodes vaporariorum. In a microscopic analysis of the salivary glands, we have shown that each primary salivary gland is composed of at least 13 cells varying in morphology and staining differentially, while the accessory salivary glands are composed of four morphologically similar cells. We analyzed the course of the alimentary canal in B. tabaci, demonstrated the internal morphology of the organs, and clarified the location of the filter chamber relative to other organs in the whitefly. Our observations confirm that the pair of structures extending from the connecting chamber are caeca that may aid in fluid movement through the midgut and are not Malpighian tubules, as previously suggested. We confirm an earlier finding that the whitefly lacks Malpighian tubules, having instead specialized Malpighian-like cells within the filter chamber at the juncture with the internal ileum. Finally, we provide the first scanning electron microscopic analysis showing the reproductive organs of B. tabaci. Our investigation provides clarified terminology for several components of the digestive and excretory system. We also provide drawings and micrographs that will aid future researchers in localizing the internal organs of B. tabaci. We expect our analysis to provide a valuable tool for studying B. tabaci / plant virus interactions and physiological and biological aspects of this insect. © 2001 Wiley-Liss, Inc.

Abstract:

The biological and molecular characterization of a virus recognized as a distinct begomovirus species, Tomato curly stunt virus (ToCSV), first observed in South Africa in 1997, is reported here. Whitefly-transmission and host-range studies were carried out using a Bemisia tabaci colony identified as the B-biotype. The experimental host range of ToCSV spanned primarily species in the Solanaceae and Fabaceae. The complete ToCSV genome (2.766 kb) was amplified by PCR, cloned, and the DNA sequence determined. Phylogenetic analysis revealed that ToCSV was most closely related to Tobacco leaf curl Zimbabwe virus (TbLCZV), at 84% nucleotide identity, indicating that ToCSV is a new species in the genus Begomovirus that is probably endemic to southern Africa. The ToCSV genome sequence contained all of the hallmark coding and non-coding features characteristic of other previously recognized monopartite begomoviruses. ToCSV is only the second begomovirus described from southern Africa that infects solanaceous species. Neither a begomoviral DNA-B component nor a satellite-like DNA molecule was detected by PCR in extracts of ToCSV-infected plants. © 2008 The Authors.

Xie, W., Chen, C., Yang, Z., Guo, L., Zhou, X., Wang, D., Chen, M., Huang, J., Wen, Y., Zeng, Y., Liu, Y., Yang, X., Xia, J., Tian, L., Cui, H., Jiao,X, Wu, Q., Wang, S., Xu, B., Li, X., Tan, X., Ghanim, M., Pan, H., Ren, S., Qiu, B., Chu, D., Delatte, Maruthi, H.M.N., Ge, F., Zhou, X., Wang, X., Wan, F., Du, Y., Luo, C., Yan, F., Preisser, E.L., Zhao, J., Gao, Q., Xia, J., Liu, Y., Yin, Y., Brown, J.K., and Zhang, Y. 2017. The invasive Q-type Bemisia tabaci genome: a tale of gene loss and gene gain. Gigascience (accepted with revision).

Chingandu, N., Zia-Ur-Rehman, M., Sreenivasan, T.N., Surujdeo-Maharaj, S., Umaharan, P., Guttierez, O.A., and Brown, J.K. 2016. Previously-elusive badnaviruses associated with symptomatic cacao in Trinidad, the first cacao-infecting viruses in the New World. Arch. Virol. doi:10.1007/s00705-017-3235-2.

Varsani, A., Navas-Castillo, J., Moriones, E., Hernández-Zepeda, C., Idris, A.M., Brown, J.K., Zerbini, F. M., Martin, D.P. 2014. Establishment of three new genera in the family Geminiviridae: Becurtovirus, Eragrovirus and Turncurtovirus. Arch. Virol. 159: 2193-2203.